Apparatus for coating pipe



April 12, 1938. w. M K. BYWATER I APPARATUS FOR COATING PIPE Filed July 27', 1955 INVENTOR M'lfrea/ MByu a fer ATTORNEY Patented Apr. 12, 1938 PATENT OFFICE APPARATUS FOR COATING PIPE Wilfred McKinley Bywater, Weehawken, N. J., assignor to The Barrett Company, New York, N. Y., a corporation of New Jersey Application July 27, 1935, Serial No. 33,436

4 Claims.-

This invention relates to coating pipe and, more particularly, to an apparatus for coating sections of a pipe line with a bituminous or other protective enamel in heat-liquefied condition to 5 protect the line against corrosion, soil conditions and stresses encountered by underground pipe lines.

It is an object of this invention to provide an apparatus for coating pipe lines which in operation results in a saving of coating material, as compared with prior apparatus for coating pipe lines. Other objects and advantages of this invention will be apparent from the following description.

l5 Heretofore, a customary practice of coating pipe lines involved rotation of a pipe section and the application of the coating material to the rotati ng pipe by an applicator who walked along one side of the rotating pipe while another person on the other side of the pipe spread the coating material poured by the first mentioned applicator over the surface of the rotating pipe. In some cases, instead of the operator manipulating the spreader, a sling was employed beneath 25 the pipe, the sling being relatively narrow, and moved along the under surface of the pipe as the operator carrying the pouring bucket walked along the pipe and applied the coating material to the top of the pipe. The sling served much the same 30 function as the spreader in the first mentioned procedure, to wit, it distributed the coating material substantially uniformly about the surface of the pipe.

The present invention is directed to a pipe coat- 35 ing apparatus in which a supply of protective coating material, which may be the mica-pitch composition of Eckert Patent No. 1,773,131, dated August 19, 1930, or other bituminous compositions such as asphalt or coal tar pitch employed for 40 protecting pipe lines, is maintained in a trough or other container of a length approximately equal to the length of a section of the pipe to be coated. This supply is disposed so that when it is caused to flow onto the pipe, it strikes the pipe 45 preferably at a. point just past the top center of the pipe in the direction of rotation. A spreader is positioned beneath the bulk supply of coating material in contact with the rotating pipe, and functions to uniformly distribute the coating ma- 50 terial poured onto the pipe about the surface thereof during the rotation of the pipe. By employing a bulk supply in a trough of substantial length, e. g. 10-20 feet, and preferably of a length approximately equal to the length of a section of the pipe to be coated (not including the end portions left bare for the application of couplers) the amount of coating material poured onto the pipe can be carefully regulated so that a proper amount of coating material to obtain the desired thickness of coating is applied. 5 ,Hence, not only does this invention result in an economy of coating material, in that substantially no coating material is wasted, but a uniform and desired thickness of coating is obtained. Moreover, by applying the coating material from 10 a bulk supply maintained in a container of a length equal to the length of the pipe section it is desired to coat, the entire length of the section is coated simultaneously. Hence, as compared with prior practice, there is a substantial saving of time, approximately equal to the time required for the applicator to Walk along the pipe section and pour coating material thereon.

The coating material should be at a temperature so that it pours freely onto the topof the rotating pipe and sets soon after application to form a glossy coating. Employing mica-pitch having a melting point of from about 150 to about 200 F., the preferred range of temperature at which the bulk supply is maintained is from about 325 to about 400 F. It is important to maintain-the wiper or spreader in contact with the pipe at a pressure such that the coating material is not stripped from the pipe, and yet suflicient to smooth the coating material about the pipe. The wiper should be held in contact with the pipe long enough to smooth the enamel, but not long enough to adhere to the coating material. The trough containing the bulk supply of coating material should be tilted tosu'ch an angle that the coating material pours uniformly at a speed proportionated to the lineal velocity of the surface of the rotating pipe.

In the accompanying drawing forming'a part of this specification, and showing for purposes of 40 exemplification a preferred form of coating apparatus of this invention, without limiting the claimed invention to such illustrative instance: Fig. 1 is an end elevation partly in section of apparatus which may be employed to coat pipe in accordance with this invention; Fig. 2 is a front elevational view of the apparatus of Fig. 1, and Fig.- 3'is an end elevation partly in section of a modified form of apparatus in accordance with this invention.

Referring to the drawing, reference numeral 1 indicates a. rolling rig on which pipe 2 may be suDpOIted and rotated by rotary movement im-- parted to the rolls i by a motor or other suitable drive such as pulley 3 arranged to receive a driving belt. In the embodiment shown on the drawing flanged rolls 4 mounted on shafts 5 journaled in frame members 6 are employed. The rolling rig for supporting and rotating the pipe may be of any suitable type, well known in the art, and therefore need not be further described. Pipe 2 may be rotated at about 125 to 190 revolutions per minute, depending on the diameter of the pipe, the viscosity and melting point of the enamel applied and like factors. Larger pipe is rotated slower than smaller pipe; the rate of rotation is less than will result in enamel being thrown from the pipe by centrifugal force.

Mounted in standards or supports 6 is a trough I of a length equal to that of the pipe section to be coated. Trough 1 has fixed to the ends thereof stub shafts 8 which are arranged to be disposed in bearings 9 in the supports 6 of the machine, and permit the trough to be rotated from horizontal position as shown in the drawing, in which position a bulk supply of coating material is maintained in the trough, to an inclined position to effect discharge of the coating material onto the top of the rotating pipe at the point indicated by the reference numeral II. A hand wheel I2 is keyed to one of the stub shafts 8 and may be actuated to move the trough I from horizontal to inclined position.

Suitably secured to the crossbar l3 extending across the machine and pivotally mounted on the supporting standards 6 as indicated at M, is a wiper l5 which preferably is of metal and has one end curved as indicated by the reference character l6. Handles I'I extend from the ends of the crossbar l3. By moving the handles I! the pressure exerted by the wiper. I5 on the rotating pipe may be controlled as desired.

In operation, a predetermined amount of coating material, such as mica-pitch in heat-liquefied condition, is introduced into trough I while it is in horizontal position, and this material maintained in heat-liquefied condition in the trough. If desired, the trough may be provided with electric heaters or other heating means.

The rolling rig is then put in operation to rotate the pipe 2 in the direction indicated by the arrow I8. The trough is then moved in the direction indicated by arrow I9 so as to cause the coating material to pour uniformly from the trough in a stream of a width equal to the length of the pipe onto the rotating pipe. The stream of coating material strikes the pipe at the point indicated by the reference character H and, as the pipe rotates, the coating material passes into contact with the wiper l5, which spreads it uniformly about the surface of the pipe. After'completion of the coating of one pipe section, the apparatus may be moved to coat a contiguous pipe section, or the pipe sections may successively be placed in a stationary machine, coated, and then removed. Sections as long as twenty to forty feet or more may be coated in accordance with this invention.

The modificationof Fig. 3 differs from that of Figs. 1 and 2 chiefly in the use of a sling type wiper or spreader instead of the wiper IS. The sling type wiper comprises a flexible sheet 2| such as canvas of a length equal to that of the pipe section to be coated and of a width sufficient to extend around the base portion of the pipe, as indicated in Fig. 3. End 22 of the wiper is secured to a fixed crossbar 23 extending across the machine and preferably bolted to the framework of the machine. End 24 is secured to a crossbar 25 which is free, i. e., is not secured to the machine as in the case of crossbar 23. A halter or rope 28 is attached to the crossbar 25. At points 21 and 28, intermediate the ends 22 and 24 of the sling, crossbars 29 and 30 are suitably secured to the sling. Springs 3| and 32 extend from the cross-bars 29 and 30 to'points on the framework of the machine and are tensioned to hold the sling away from the pipe, as shown in full lines, Fig. 3. The operator by pulling a halter 26 can move the sling against the action of the springs 3| and 32 into contact with the pipe as shown in dotted lines on Fig. 3.

The operation of the apparatus of Fig. 3 is much the same as hereinabove described in connection with Figs. 1 and 2, except that the operator spreads the coating material uniformly about the rotating pipe by means of the sling spreader 2| instead of the wiper or spreader l5 of Fig. 1. In both modifications it will be noted that the halter or handle effecting the operation of the sling or spreader l5 respectively and the hand wheel 8 for moving the trough I are on the same side of the pipe, 50 that one and the same operator can effect the discharge of the coating material onto the pipe and control and regulate the spreading of this material about the pipe during its rotation.

It is to be understood that this invention is not restricted to the present disclosure, otherwise than defined in the appended claims.

What is claimed is:

1. Apparatus for coating pipe comprising, in combination, means for rotating the pipe and a trough of a length equal to that of the section of the pipe to be coated, constructed and mounted to tilt on its longitudinal axis to feed coating material to the top of the pipe.

2. Apparatus for coating pipe comprising, in combination, means for rotating the pipe, a

section of the pipe to be coated constructed and mounted to tilt on its longitudinal axis to feed coating material to the top of the pipe, and a mounted to tilt on its longitudinal axis to feed coating material to the top of the pipe, a spreader of a length equal to the section of the pipe to be coated pivotally mounted beneath the trough, and means for moving the spreader into contact with the pipe.

4. Apparatus for coating pipe comprising, in combination, means for rotating the pipe, a trough of a length equal to the length of the section of the pipe to be coated constructed and mounted to tilt on its longitudinal axis to feed coating material to the top of the pipe, a sling type spreader constructed and arranged to extend beneath the lower portion of the pipe, said spreaderhaving one end secured and the other end free, spring means for holding said spreader out of contact with the pipe, and means for moving the free end of the spreader so as to move the spreader into contact with the pipe against the tension of said spring means.

WILFRED McKINLEY BYWATER.

' trough of a length equal to the length of the 

